Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 151610

Area Forecast Discussion
National Weather Service Northern Indiana
1110 AM EST Thu Feb 15 2018

Issued at 300 AM EST Thu Feb 15 2018

A mild and moist airmass will continue to produce fog and areas of
drizzle this morning. Areas of fog and more widespread rainfall is
expected this afternoon into this evening as a storm system tracks
through the region. Highs today will reach from the mid to upper
40s in Michigan to near 60 degrees in east-central indiana and
northwest Ohio. Cooler and drier air will filter into the region
Friday into early Saturday, followed by chances for light snow
later Saturday and Saturday evening. The pattern next week will
feature more mild and occasionally wet weather.


Issued at 1110 AM EST Thu Feb 15 2018

Extended dense fog advisory through the afternoon. Latest hi-res
guidance still showing dense fog through the evening. Some
improvement possible as rain spreads across the area later this
afternoon but morning obs still show a deep snowpack across our
N/NW counties. Southern fringes of advisory may clear out sooner
but suspect South Bend will remain around 1/4 mile through
midafternoon and even further extensions may be necessary.


.SHORT TERM...(Today and Tonight)
Issued at 300 AM EST Thu Feb 15 2018

Widespread dense fog and patchy drizzle will remain the story this
morning as pronounced low level moisture and moisture release
from an extensive snowpack supports an increasingly
moist/saturated near surface layer. The only exception may be
along and southeast of US 24 where current ob trends, better
mixing, and lacking snow cover hint a lesser impact from fog. The
fog along/northwest of US 24 may linger well into the
afternoon/evening, though confidence in impacts and extent of
M1/4sm visibilities wane with time.

Frontal wave in low amplitude wsw flow still on tap to provide more
widespread shower activity this afternoon into early this evening
across the entire forecast area. Model xsections somewhat aggressive
in greatly reducing stability within the strengthening elevated
frontal zone during this time. A more convective look to the
precipitation is expected as a result, though point thunder chances
remain too low/uncertain for a locally heavy rainfall/thunderstorm
mention at this time.


.LONG TERM...(Friday through Wednesday)
Issued at 300 AM EST Thu Feb 15 2018

Subsident/dry airmass in wake of the frontal wave and associated
positively tilted shortwave trough will yield of transient shot of
cooler/drier wx into Friday and Saturday morning. Trailing
shortwave energy in energetic quasi-zonal flow has the potential
to generate a brief period of light snow Saturday
afternoon/evening, though significant differences remain in
guidance resulting in a mid chc PoP. Dry/seasonable otherwise this

Mild and occasionally wet wx then becomes the focus into next week
as southeast ridging amplifies in response to renewed Western Conus
troughing. Deep Gulf of Mexico moisture transport into a burgeoning
baroclinic zone in between these larger scale features from the
Southern Plains northeast into the Mid MS Valley/Great lakes will
provide the higher chance for rainfall...though details on where
heavier rainfall will fall remains uncertain. Will continue to
carry likely PoPs and mention potential flooding concerns in the


.AVIATION...(For the 12Z TAFS through 12Z Friday Morning)
Issued at 635 AM EST Thu Feb 15 2018

LIFR conditions continue at KSBN and will likely persist into this
evening before some improvement late tonight once cold front
passes and northwest flow brings drier air into the area. Most
hires guidance keeps KSBN VIS at 1/4sm through at least 03z/16.
Did try to be a bit optimistic with subtle improvement to a half
mile with mixing as rain develops. Lack of snow cover at KFWA
helping keep VIS in the IFR to MVFR range but cigs stuck in IFR
category. This trend expected to continue today as well with
light to occasionally moderate rainfall developing. Cannot rule
out some isolated thunder today but too small of a chance for
inclusion in point forecasts. Some improvement expected late
tonight once stronger northwest flow pushes in with drier air.


IN...Dense Fog Advisory until 5 PM EST /4 PM CST/ this afternoon for

MI...Dense Fog Advisory until 5 PM EST this afternoon for MIZ077>081.

OH...Dense Fog Advisory until 5 PM EST this afternoon for OHZ001-002.



SHORT TERM...Steinwedel
LONG TERM...Steinwedel

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